The electronics industry has experienced an ever increasing demand for smaller and faster electronic devices which are simultaneously able to support a greater number of increasingly complex and sophisticated functions. Accordingly, there is a continuing trend in the semiconductor industry to manufacture low-cost, high-performance, and low-power integrated circuits (ICs). Thus far these goals have been achieved in large part by scaling down semiconductor IC dimensions (e.g., minimum feature size) and thereby improving production efficiency and lowering associated costs. However, such scaling has also introduced increased complexity to the semiconductor manufacturing process. Thus, the realization of continued advances in semiconductor ICs and devices calls for similar advances in semiconductor manufacturing processes and technology.
As one example, the effort to increase IC functionality within a reduced area has led to the introduction of 3D-IC designs. In such designs, multiple layers of active electronic devices are vertically integrated, for example within a single substrate or by using stacked substrates. 3D-IC designs can offer improved performance (e.g., due to shorter interconnects) as well as heterogeneous functionality (e.g., logic, memory, image sensors, MEMS, etc.) in a reduced form factor. One important tool in the development of 3D ICs has been through silicon via (TSV) technology, which provides an electrically conductive path between a front- and back-side of a substrate, providing for the vertical stacking of multiple die (or “chips”). However, stacked die which utilize TSVs also present challenges such as interconnect routing and cell placement, and transistor reliability, among others.
Some of the challenges of TSV implementation have been addressed with the introduction of silicon interposers. Silicon interposers can be used for TSV formation while not containing any active devices, thus mitigating issues introduced in active die which contain TSVs. Moreover, an interposer disposed between stacked die can be used to rewire connections between each of the stacked die, for example by reconfiguring an input/output (I/O) count between a front-side and a back-side of the interposer.
While TSVs and silicon interposers have been key enablers for 3D-IC technology, continued improvements in system integration and bandwidth require even higher device and I/O density, reduced power consumption, and improved access times (e.g., to memory blocks), all within an ever-reducing form factor. Accordingly, improved semiconductor packaging solutions for 3D-IC systems, which provide high density I/O configurations while maintaining a compact design, are desired.